In many cases, a tape is wound around a wire harness including a large number of electric wire bundles wired in a vehicle, so as to bundle and protect the electric wire bundles. In recent years, the tape wrapping is not used for the reduction of working man-hours. A sheet, which is bonded to the electric wire bundles at once so as to bundle and protect the electric wire bundles, is increasingly used.
As illustrated in FIGS. 16(a) and 16(b), an adhesive layer is formed on only one surface of a wire harness sheet 501. An electric wire bundle 503 is protected by peeling release paper off the wire harness sheet 501, by setting the electric wire bundle 503 at a designated position on the wire harness sheet 501, and by bonding together adhesive surfaces.
FIG. 17 is a plan view illustrating main portions of a wire harness sheet that is folded back and adhesively fixed to a bending portion of an electric wire bundle, and illustrating a wire harness.
A wire harness sheet 531 illustrated in FIG. 17 is formed of a piece of sheet base material 529, and an adhesive layer is provided on only one surface of the wire harness sheet 531. The wire harness sheet 531 is folded back along a broken line portion 523, and is adhesively fixed to a bending portion 527 of an electric wire bundle 525.
FIG. 18 is a plan view illustrating main portions of wire harness sheets that overlap each other and are adhesively fixed to the bending portion of the electric wire bundle, and illustrating a wire harness.
A wire harness sheet 541 illustrated in FIG. 18 is formed of two pieces of sheet base materials 543 and 545, and an adhesive layer is provided on only one surface of each of the sheet base materials 543 and 545. The adhesive layers overlap each other, while facing each other, and are adhesively fixed to the bending portion 527 of the electric wire bundle 525. A sheet base material is required to be cut to a bending shape of the electric wire bundle 525 so as to obtain the wire harness sheets 531 and 541 of the related art.
As illustrated in FIG. 19(a), PTL 1 discloses a wire harness branched portion protective structure in which a protective sheet 513 having an adhesive layer on a back surface thereof is wound around and is fixedly attached to a T-shaped harness branched portion 511 in which a branch wire 509 branches off from a main wire 507.
The protective sheet 513 has a crossed shape in which slits 521 are formed on both ends of a cross-shaped connection portion 519 that connects a vertical portion 515 and a horizontal portion 517. As illustrated in FIG. 19(b), the protective sheet 513 is fixedly attached to the main wire 507 and the branch wire 509 by winding the cross-shaped connection portion 519 around an outer circumferential surface of the main wire 507, the outer circumferential surface being positioned opposite to a branched portion, and by respectively winding both the horizontal portions 517 in a spiral shape around the entire outer circumferential surfaces of the main wire 507 on both sides of the branched portion in such a manner that parts of the horizontal portion 517 overlap each other. In contrast, both sides of the vertical portion 515 are fixedly attached to facing semi-circumferential surfaces of the branched portion 511, respectively, the outer semi-circumferential surface ranging from the main wire 507 to the branch wire 509. Both vertical portions 515 are bonded together and fixedly attached together on both sides of the main wire 509. In doing so, the protective sheet 513 covers the entire outer circumferential surfaces of the main wire 507 and the branch wire 509 at a branch position.